The Dumbarton Oaks Conference (or Washington Conversations on International Peace and Security Organization) was an international conference at which the United Nations was formulated and negotiated.
The conference's discussions on the make-up of the UN included which states would be invited to be members, the formation of the United Nations Security Council, and the right of veto that would be given to the Security Council's permanent members.
Hilderbrand, Robert C. (1990). Dumbarton Oaks: The Origins of the United Nations and the Search for Postwar Security. Chapel Hill: University of North Carolina Press. ISBN 0-8078-1894-1.